1. Field
The present invention relates generally to communication and more specifically to techniques for combining acknowledgement (ACK) message with assignment message and transmitting both messages using a single channel.
2. Background
Wireless communication systems are widely deployed to provide various types of communication such as voice, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. Typically, a wireless communication system comprises several base stations, wherein each base station (or access point) communicates with the mobile station using a forward link (FL) and each mobile station (or access terminal) communicates with base station using a reverse link (RL).
Most of the communication system described above use a forward link and a reverse link in conjunction with a Hybrid Automatic Repeat Request (H-ARQ) scheme to communicate data and other information. H-ARQ techniques have been shown to provide significant improvement in capacity. With Hybrid ARQ, a packet is sent using multiple transmissions. The packet transmission could be terminated early if the receiver can decode the packet prior to receiving all the transmission. However, in order for early termination, the receiver (or recipient) must provide some acknowledgement that the data was received properly. Generally ACK or not ACK (NACK) messages are used to provide such acknowledgement to the transmitting entity (or sender). In a typical system, a separate ACK channel is established on forward and reverse link which is then used to provide the ACK/NACK messages to the sender. However, since ACK messages are very small (1-2 bits), it is extremely expensive to encode and CRC protect individual ACK messages to achieve the required reliability. This is especially true since the number of ACKs increase as the number of user using the reverse link increase. In order to keep up with the throughput, the system would need to adjust the resources. It is burdensome and at times inefficient to separately encode each ACK message and dedicate a channel for transmitting the ACK messages.
Thus, there is a need for a system and method to provide acknowledgement to the sender efficiently to combine the ACK messages with other communication between transmitter and receiver without using a dedicated resource.